People purchase products from many different merchants using a variety of different payment options. The transactions for these purchases typically are confirmed by physical in-store receipts or by electronic confirmation messages that are addressed to the purchasers' messaging accounts (e.g., a purchaser's electronic mail account). The large number and diversity of confirmation messages makes it difficult for people to track their purchases and obtain a comprehensive understanding of their purchase histories. In addition, the large diversity of merchants from which people purchase products makes it difficult for merchants to obtain sufficient purchase history data to develop accurate customer profiles. Even assuming that a person uses a common identifier (e.g., a loyalty card or credit card) for all his or her purchases, these purchases typically are tracked only by the merchant that issued the identifier to the customer. This lack of customer information limits the ability to effectively determine customers' cross-merchant purchase transaction information.
In an effort to ameliorate these problems, reporting systems have been developed to extract purchase related information from data sources that are published directly by merchants to consumers, such as purchase confirmation messages and shipping confirmation messages.